DESCRIPTION (provided by investigator): Advances in lung cancer treatment have resulted in increased opportunities for long term (>5 year) survival. However, these lung cancer survivors, more so than most other cancer survivors, have significant additional comorbidity as a result of their lung cancer treatment, past smoking history and pre-existing diseases. Sleep disorders, such as insomnia, are especially common. Preliminary investigations have shown that the majority of these lung cancer survivors suffer from insomnia at rates higher than survivors of most other cancers, that this insomnia is associated with significant impairments in quality of life even when controlling for other symptoms such as dyspnea, and that mortality rates may be higher in those with insomnia. This application seeks to extend these findings by conducting a study in 280 long-term lung cancer survivors that incorporates polysomnography and pulmonary function measurements in a longitudinal design with a one-year follow-up reassessment;this is a novel approach in this patient population. The proposed study is thus uniquely designed to test the hypotheses that sleep disorders are common in lung cancer survivors and are associated with significant sequelae. It will address several key specific aims: 1) identify the prevalence of sleep disorders in lung cancer survivors using polysomnography, the only accurate method to identify sleep-related breathing disorders, amongst others;2) determine the risk factors for insomnia;and 3) determine the longitudinal outcomes of insomnia. In addition to exploring the interaction of comorbid conditions and sleep disorders in lung cancer survivors, the proposed study will also examine the effects of age-related changes in the sleep-wake drive, such as altered melatonin levels. The overall feasibility of this application is enhanced by the access to a large survivor population from an active cardiothoracic surgery practice and the past experience of the research team as demonstrated by their preliminary data. The study is also adequately powered to address several specific hypotheses that are relevant to the clinical care of cancer survivors. Exploratory analyses include comparisons with a pre-existing dataset of 420 older non-cancer subjects to allow for comparison of sleep parameters. An important developmental aspect of the protocol is that the investigators will conduct exploratory multivariate analysis. This will be used to provide more accurate point estimates for sample size calculations for the design of future studies in lung cancer survivors and identify potential areas for future intervention studies. The findings from this study thus have the potential to significantly advance our understanding of the etiology and consequences of sleep disorders in cancer survivors, improve the clinical care they receive, and lay the groundwork for future investigations in this relatively understudied area. PUBLIC HEALTH RELEVANCE: Sleep disorders such as insomnia are common in lung cancer survivors, yet relatively little research has been done in this area and past studies have not included tests to diagnose common sleep disorders such as sleep apnea (abnormal breathing during sleep). The proposed study will use more accurate sleep tests (also known as polysomnographies) and follow patients over time to determine if sleep disorders can lead to increased risks of negative outcomes. This information will help physicians to better understand and treat sleep problems in cancer survivors.